Gemstone having a mirror-coated front

ABSTRACT

Gemstone ( 1 ) having a back ( 2 ) tapering to a tip ( 3 ), and a front which is cut in a faceted manner ( 5 ), wherein regions opposing said tip ( 3 ) being mirrored ( 12 ).

The invention relates to a gemstone having a back which tapers to a tip, and a front which is cut in a faceted manner.

In order to obtain an inexpensive alternative to genuine diamonds, gemstones made of glass or plastic material or else artificial precious stones, such as for example zirconia, have been used for a relatively long time. In this case, the gemstones made of glass or plastic material and also the artificial precious stones have surfaces which are cut in a faceted manner in order to imitate the fire of a diamond as accurately as possible.

Nevertheless, as the above-cited imitations, in particular those made of glass or plastic material, have a lower index of optical refraction than diamond, making the geometrical conditions for total reflection more difficult to fulfill, an imitation of this type can never match the brilliance of a genuine diamond.

Gemstones usually have in this case a back which tapers to a tip and is separated from the front by what is known as the girdle. In addition, the front can have a table. This design resembling the brilliant cut of a diamond is conventionally referred to in the trade as a chaton.

For the above-mentioned reasons, it is known in the art to provide the back of the glass stone with a mirroring in order in this way to match the different beam paths in diamond and glass or plastic material resulting on account of the very different indices of refraction. The mirrored back is then arranged in a carrier and therefore serves as the positioning face of the gemstone. The front opposing the back faces the viewer and serves as the visible face of the gemstone. Chatons mirrored in this way are for example disclosed in AT 236 154, DE 24 06 008 and also DE 24 44 705 A1.

DE 1 079 872 discloses a gemstone which is made of plastic material and has a front which is cut in a faceted manner and tapers to a tip, and a cylindrical back, a metallic mirror coating being applied to the base of the cylinder.

Further gemstones having a flat back used to fasten the gemstones to a carrier material are also known in the art. Gemstones of this type made of glass or plastic material are generally referred to as roses.

AT 006 065 U1 also presents a chaton having a back which tapers to a tip, with which the chaton is applied to a textile backing, for example, and which is mirrored.

The object of the invention is to develop the teaching presented in the prior art for imitating the brilliance of a diamond and to provide inexpensive gemstones which imitate the brilliance of a diamond more accurately.

This is achieved by a gemstone having the features of claim 1.

The fact that a gemstone according to the invention has a back tapering to a tip and a front cut in a faceted manner, regions of the front, i.e. regions lying opposite the tip, being mirrored, allows the back which tapers to a tip to be used as the visible side of the gemstone, in contrast to the prior art. This allows, in contrast to a conventional chaton, the visible face of which forms the front along with the table, novel visual effects to occur resulting on account of the refraction of light at the back tapering to a tip. At the facets of the front, which are at least partially mirrored, the beams of light are reflected, the facets, in particular the edges between the facets, producing further visually attractive light effects. In this case, provision may be made for the front of the gemstone according to the invention, which front serves, on account of the mirroring, as the positioning face, itself to have no tip. With the front embodied as the positioning face, the gemstone can then be arranged on or in a carrier body.

Further advantageous embodiments of the invention are defined in the dependent claims.

In a particularly preferred embodiment of the invention, the entire front which is cut in a faceted manner, is mirrored, thus further intensifying the above-described effect on account of the reflection of light at the facets, in particular in the region of the edges between the facets.

Furthermore, provision is preferably made for the back which tapers to a tip and serves as the visible face to be cut, a facet cut being exceptionally preferred. As a result, the side facing the viewer is also embodied in a visually elegant manner and can produce attractive visual effects on account of the refraction of light at the facets, in particular at the edges between the facets. In this case, provision may be made for a substantially circular girdle to separate the front from the back. From the circular girdle, eight planar faces can for example then taper to a tip and as a result form a back cut in a faceted manner. Provision may also be made for the front cut in a faceted manner to be formed by eight planar faces extending forward from the girdle.

In this case, provision may be made for the opening angle of the tip of the back to be in a range between 90° and 102°, preferably between 94° and 98°.

In a particularly preferred embodiment, the front has a table. In this case, as a development of the above-described example, the front formed by eight faces extending forward from the girdle can end as a table embodied as a regular octagon. In this case, the diameter of the table can be between 0.6 times and 0.95 times, preferably between 0.7 times and 0.9 times, the diameter of the gemstone that is provided by the diameter of the face separating the front from the back or that is the diameter of the girdle if such a girdle is present.

A gemstone of this type having a back which tapers to a tip and may in one embodiment be rounded off in the form of a culet, and a front which is cut in a faceted manner and has a table, wherein the front can be separated from the back by a circular girdle, is thus a chaton. In contrast to the previous prior art, now precisely the front is mirrored, whereby extremely visually attractive effects are produced on account of the reflections caused by the mirroring at the facets and also at the table and at the edges between these faces. In this case, it may be preferable for the ratio of the height of the front to the height of the back to be in a range between 3 and 7, preferably between and 4 and 6. Furthermore, provision may be made for the ratio of the diameter of the table to the diameter of the girdle to be between 0.6 and 0.95, preferably between and 0.7 and 0.9.

In a particularly preferred embodiment, the gemstone according to the invention is made of glass, resulting in inexpensive manufacture. Nevertheless, glass stones cut in a faceted manner have a high-quality, very visually attractive appearance. However, provision may also be made for the gemstone according to the invention to be made of plastic material and be injection-molded, for example.

In a preferred embodiment, the mirroring is embodied as a reflective layer, it being preferable for this reflective layer to be vapor-deposited onto the corresponding regions.

The invention further relates to a composite body with a carrier and at least one gemstone which is arranged in the carrier and is embodied as stated above, the at least one gemstone being arranged with the mirrored region in the carrier. The carrier itself can be made of any desired material.

The gemstone is thus arranged with its front, i.e. with the positioning face, in the carrier. It may in this case be preferable for the gemstone to be adhesively bonded to the carrier or stuck onto the carrier. For this purpose, it is possible to arrange on the front, in addition to the mirroring which is embodied as a reflective layer, for example, an adhesive layer with which the gemstone is stuck onto the carrier. Possible adhesives used for this purpose are conventional adhesives known per se in the art. These can be cured, for example by increasing the temperature or by applying UV radiation.

In one embodiment of the invention, the composite body has a recess in which the gemstone can be arranged. The recess has in this case a geometrical shape and size corresponding to the front of the gemstone.

Further details and advantages of the present invention will be commented on hereinafter in greater detail based on the description of the figures and with reference to the drawings, in which:

FIGS. 1 a to 1 d are a plan view, a side view and a view from below of an embodiment of a gemstone according to the invention and also a further side view to illustrate the geometrical sizes;

FIGS. 2 a to 2 c are a plan view, a side view and a view from below of a further embodiment of a gemstone according to the invention;

FIGS. 3 a to 3 c are a plan view, a side view and a view from below of a further embodiment of a gemstone according to the invention;

FIG. 4 is a side view of a further embodiment of a gemstone according to the invention; and

FIGS. 5 a and 5 b are a plan view and a cross section through a composite body consisting of gemstones according to the invention arranged in a carrier.

The gemstone 1 illustrated in FIGS. 1 a to 1 d is made of glass and has a back 2 tapering to a tip 3, eight planar faces 4 tapering, as is conventional in gemstones sold in the trade under the name “chaton”, from a marginal edge 9 forming a regular polygon to the tip 3. The planar faces 4 form the facets of the back 2 of the gemstone 1. A girdle 10 can also be arranged instead of the marginal edge 9.

The side view of FIG. 1 b shows that the gemstone 1 according to the invention has a front 5 cut in a faceted manner, eight planar faces 6 extending forward in a beveled manner, starting from the marginal edge 9, and ending in this case in a planar table 7 embodied as a regular octagon. The front 5 is provided with a mirroring 12, so that the edges of the front 5 are indicated by broken lines, as these are arranged under this mirroring 12 which is preferably embodied as a reflective layer. The mirroring 12 itself is not explicitly shown. Preferably, this mirroring 12 is provided by a reflective layer arranged, for example vapor-deposited, on the outer wall of the gemstone 1.

FIG. 1 c is a view from below onto the gemstone 1 according to the invention, showing the table 7 embodied as a regular octagon, the eight planar faces 6 of the front 5 and also the marginal edge 9 between the front 5 and back 2.

FIG. 1 d shows the geometrical sizes of a gemstone 1 according to the invention. The overall height of the gemstone 1 is obtained from the distance between the tip 3 and table 7, this height being measured perpendicularly onto the table 7. The diameter D_(S) of the gemstone 1 is measured perpendicularly to this height, i.e. parallel to the table 7. The plane of this diameter D_(S) separates the front 5 from the back 2, the back 2 having a height H_(R) and the front 5 having a height H_(V). The table 7 has a diameter D_(T). The back 2 of the gemstone 1 has at the tip 3 an opening angle α. The angles of the lateral faces 4 and 6 respectively are measured with respect to the plane containing the diameter D_(S). The angle of the lateral faces 4 of the back 2 is in this case denoted by β, whereas the angle of the lateral faces 6 of the front 5 is denoted by γ.

FIGS. 2 a to 2 c show a further embodiment of a gemstone 1 according to the invention, the only difference from the gemstone of FIG. 1 a to 1 d consisting in the fact that the tip 3 is rounded off or flattened to form a culet 8. Again, as may be seen in FIG. 2 b, the faces 6 of the front which is cut in a faceted manner 5 and also the table 7 are mirrored, so that the edges arranged there are arranged under this mirroring coating 12 and are therefore indicated by broken lines.

FIGS. 3 a to 3 c show a further embodiment, the only difference from the gemstone 1 illustrated in FIGS. 1 a to 1 d consisting in the fact that a substantially circular girdle 10, which separates the back 2 from the front 5, is arranged instead of a marginal edge 9. The diameter D_(S) of the gemstone 1 is in this case provided by the diameter of the substantially circular girdle 10. Again, the front 5 is mirrored 12.

A further embodiment of the invention is illustrated in FIG. 4. A gemstone 1 of this type is commonly known in the trade as a double tip. The back 2 is again cut in a faceted manner with eight planar faces 4 which taper to a tip 3. A marginal edge 9 separates the back from the front 5 which also has eight planar faces 6 which taper to a tip 14. A mirroring 12, for example in the form of a reflective layer, is arranged on the front 5. For this reason, the rims of the front 5 are indicated by broken lines.

FIG. 5 a shows a composite body 11 consisting of a carrier 13 and a large number of gemstones 1 according to the invention arranged in the carrier 13. The gemstones 1 are in this case arranged uniformly in rows and columns. However, it would also be possible for any desired pattern to be formed by the gemstones 1.

FIG. 5 b is a cross section along the straight sectional line denoted by A-A in FIG. 5 a. The mirroring 12 may in this case be seen. Those regions of the gemstones 1 that are provided with a mirroring 12 are in this case arranged in the carrier 13. For this purpose, a layer with adhesive, with which the gemstones 1 are stuck on in the carrier 13, can be arranged on the mirroring 12. Beams of light which enter the gemstones 1 are reflected at this mirroring 12, as a result of which the planar faces 6 and the edges arranged between the planar faces 6, in particular, produce attractive reflective effects which can imitate the fire and the brilliance of a diamond particularly accurately.

The invention is not limited to the examples shown, but includes all the technical equivalents which may come under the scope of the following claims.

Indications of position selected in the description, such as for example top, bottom, to the side, etc. are also based on the figure which has been directly described and also illustrated and are correspondingly transferable, in the event of a change in position, to the new position. 

1. A gemstone having a back which tapers to a tip, and a front which is cut in a faceted manner, wherein regions lying opposite said tip are mirrored.
 2. The gemstone as claimed in claim 1, wherein the entire front which is cut in a faceted manner is mirrored.
 3. The gemstone as claimed in claim 1, wherein said back which tapers to a tip is cut.
 4. The gemstone as claimed in claim 3, wherein said back is cut faceted.
 5. The gemstone as claimed in claim 1, wherein said front and said back which tapers to a tip are separated by a girdle.
 6. The gemstone as claimed in claim 1, wherein said back which tapers to a tip is rounded off in the form of a culet.
 7. The gemstone as claimed in claim 1, wherein said front has a table.
 8. The gemstone as claimed in claim 1, wherein the ratio of the height of said back to the height of said front is between 3 and
 7. 9. The gemstone as claimed in claim 1, wherein the ratio of the height of said back to the height of said front is between 4 and
 6. 10. The gemstone as claimed in claim 7, wherein the ratio of the diameter of said table to the diameter of said gemstone is between 0.65 and 0.95.
 11. The gemstone as claimed in claim 7, wherein the ratio of the diameter of said table to the diameter of said gemstone is between 0.7 and 0.9.
 12. The gemstone as claimed in claim 1, wherein the opening angle of said back tapering to a tip is between 90° and 102°.
 13. The gemstone as claimed in claim 1, wherein the opening angle of said back tapering to a tip is between 94° and 98°.
 14. The gemstone as claimed in claim 1, wherein the angle of inclination of the lateral faces of said back to the diameter plane is between 36° and 48°.
 15. The gemstone as claimed in claim 1, wherein the angle of inclination of the lateral faces of said back to the diameter plane is between 40° and 44°.
 16. The gemstone as claimed in claim 1, wherein the angle of inclination of the lateral faces of said front to the diameter plane is between 36° and 48°.
 17. The gemstone as claimed in claim 1, wherein the angle of inclination of the lateral faces of said front to the diameter plane is between 40° and 44°.
 18. The gemstone as claimed in claim 1, wherein said gemstone is made of glass.
 19. The gemstone as claimed in claim 1, wherein said gemstone is made of plastic material.
 20. The gemstone as claimed in claim 1, wherein the mirroring is embodied as a reflective layer which is applied to the gemstone.
 21. A composite body with a carrier and at least one gemstone as claimed in claim 1 arranged in said carrier, wherein said at least one gemstone is arranged with the mirrored region in said carrier.
 22. The composite body as claimed in claim 21, wherein said at least one gemstone is adhesively bonded to said carrier.
 23. The composite body as claimed in claim 14, wherein said carrier comprises a recess for arranging said at least one gemstone in. 